Culicoides midges (diptera: ceratopogonidae) as vectors of orbiviruses in Slovakia.

In recent years, rapid spread of Culicoides-borne pathogens such as bluetongue (BT) and Schmallenberg viruses have been reported in Europe. In this study we examined the Culicoides populations in farms with wild and domestic ruminants in Eastern Slovakia with the aim to confirm the presence of biting midges serving as potential vectors of important pathogens. The main vector complexes were the Obsoletus complex (54%; n=4,209) and the Pulicaris complex (23%; n=1,796). To estimate the relative abundance of the cryptic species of the Obsoletus complex (Culicoides obsoletus, Culicoides scoticus and Culicoides montanus), we performed the multiplex polymerase chain reaction (PCR) based on ITS-2 and ITS-1 segments, on 125 midges randomly sampled. The relative abundance of C. obsoletus ranged from 5.26% in the farm with wild ruminants to 85.71% in another farm with cattle and sheep. A total of 112 pools of parous and gravid females belonging to the Obsoletus and Pulicaris complexes were tested for virus detection by the real-time reverse transcription polymerase chain reaction (RT-PCR) for BT virus, as well as for the Epizootic Hemorrhagic Disease Virus (EHDV), with negative results.